470 THE 4Z00LOGIST. 
NOTICES OF NEW BOOKS. 
The Mechanistic Conception of Life: Biological Hssays. By 
Jacques Lors, M.D., Ph.D., &ce. Chicago: University 
of Chicago Press. London: The Cambridge University 
Press, Fetter Lane. 
Tuis volume consists of the reprint of a number of essays 
and addresses on a subject which has recently been much dis- 
cussed in this country, and, to use words in the introductory 
essay, the question is: ‘‘ whether our present knowledge gives 
us any hope that ultimately life, 7. e. the sum of all life pheno- 
mena, can be unequivocally explained in physico-chemical terms.” 
The verdict, however, so far as these essays are concerned, may 
be given as ‘‘ non proven.” 
The problem is a complicated one, and of necessity enters 
the field of ethics, which we read ‘‘ must be influenced to a large 
extent through the answer to this question.” If, however, as 
Dr. Loeb says, it may be argued, ‘‘if our existence is based on 
the play of blind forces and only a matter of chance—if we our- 
selves are only chemical mechanisms—how can there be any 
ethics for us?” He answers his own inquiry by the opinion 
“that our instincts are the root of our ethics, and that the 
instincts are just as hereditary as the form of our body.” We 
would here desiderate a definition of both the terms “‘ instincts ”’ 
and ‘‘ ethics,” as understood in this discussion. However, we 
are now travelling beyond the purview of ‘ The Zoologist.’*; 
We.can, however, follow Dr. Loeb more easily in some of hig 
biological conclusions. Such a paragraph as the following is 
* Dr. Loeb, at p. 70, writes :—‘‘ It is evident that there is no sharp line 
of demarkation between reflexes and instincts. We find that authors prefer 
to speak of reflexes in cases where the reaction of single parts or organs of 
an animal to external stimuli is concerned; while they speak of instincts 
where the reaction of the animal as a whole is involved (as is the case 
in tropisms).’”’ But does this explain the statement on p. 31 :—‘ We struggle 
for justice and truth since we are instinctively compelled to see our fellow 
beings happy”? The italics are our own. 
